Apple CEO Tim Cook said Tuesday he is "incredibly optimistic" about the company's new partnership with China Mobile and hinted at a deeper collaboration.

Apple's chief was particularly upbeat while addressing the media before the latest iPhones go on sale Friday on China Mobile, the world's largest wireless carrier.

"We've gotten to know each other....Today is a beginning, and I think there are lots more things our companies can do together in the future," Cook told members of the media, including the Wall Street Journal.

Confirming long-standing rumors, Apple announced last month that it had finally reached an agreement with China Mobile to offer the iPhone 5S and 5C to the carrier's 760 million customers beginning January 17.

Although the iPhone is already available in China through China Unicom and China Telecom, the deal with China Mobile is expected to deliver vast numbers of new customers to Apple. Piper Jaffray analyst Gene Munster expects that Apple could sell 17 million total iPhones on China Mobile in 2014, reaching approximately 2 percent of China Mobile's total subscriber base.

Cook's comments suggest that Apple's deal with China Mobile will extend beyond mere handset sales but did not elaborate. CNET has contacted Apple for more information and will update this report when we learn more.

China Mobile Chairman Xi Guohua has said his company's customers had already ordered several million iPhones. The Journal reported on Tuesday that Apple supplier Foxconn shipped 1.4 million phones to China Mobile.